A Reader Study to Compare Multi-step vs. Standard N4ITK bias field Correction Methods in Xenon MRI

Motivation: Conducting 129Xe ventilation MRI across different imaging centers requires refined methods of bias field correction to reduce variability between images. Goal(s): To compare standardized 129Xe MRI ventilation healthy reference values generated with different bias field correction methods using a reader study. Approach: Six expert readers evaluated 133 subjects (57 healthy from 3 sites) processed with three different healthy reference distributions, including one utilizing multi-step bias field correction. The order of the methods was randomized to ensure blinding. Results: A multi-step bias field correction demonstrated superior performance with the highest perfect score rates, especially in addressing apical-basal gradient inhomogeneities across sites. Impact: This study provides valuable insights into the effectiveness of different bias field correction methods in reducing variability and improving quantification accuracy in 129Xe ventilation MRI across multiple imaging centers.